 /*******************************************************************************
  * Copyright (c) 2003, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.browser;

 import java.net.URL ;
 import java.util.Map ;
 import java.util.HashMap ;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.core.runtime.FileLocator;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.jface.resource.ImageRegistry;
 /**
  * Utility class to handle image resources.
  */
 public class ImageResource {
     // the image registry
 private static ImageRegistry imageRegistry;

     // map of image descriptors since these
 // will be lost by the image registry
 private static Map imageDescriptors;

     private static Image[] busyImages;

     private static final String URL_PREFIX = "$nl$/icons/"; //$NON-NLS-1$
 private static final String URL_CLCL = URL_PREFIX + "clcl16/"; //$NON-NLS-1$
 private static final String URL_ELCL = URL_PREFIX + "elcl16/"; //$NON-NLS-1$
 private static final String URL_DLCL = URL_PREFIX + "dlcl16/"; //$NON-NLS-1$
 private static final String URL_OBJ = URL_PREFIX + "obj16/"; //$NON-NLS-1$

     // --- constants for images ---
 // toolbar images
 public static final String IMG_CLCL_NAV_BACKWARD = "IMG_CLCL_NAV_BACKWARD"; //$NON-NLS-1$
 public static final String IMG_CLCL_NAV_FORWARD = "IMG_CLCL_NAV_FORWARD"; //$NON-NLS-1$
 public static final String IMG_CLCL_NAV_STOP = "IMG_CLCL_NAV_STOP"; //$NON-NLS-1$
 public static final String IMG_CLCL_NAV_REFRESH = "IMG_CLCL_NAV_REFRESH"; //$NON-NLS-1$
 public static final String IMG_CLCL_NAV_GO = "IMG_CLCL_NAV_GO"; //$NON-NLS-1$
 public static final String IMG_CLCL_NAV_HOME = "IMG_CLCL_NAV_HOME"; //$NON-NLS-1$
 public static final String IMG_CLCL_NAV_PRINT = "IMG_CLCL_NAV_PRINT"; //$NON-NLS-1$

     public static final String IMG_ELCL_NAV_BACKWARD = "IMG_ELCL_NAV_BACKWARD"; //$NON-NLS-1$
 public static final String IMG_ELCL_NAV_FORWARD = "IMG_ELCL_NAV_FORWARD"; //$NON-NLS-1$
 public static final String IMG_ELCL_NAV_STOP = "IMG_ELCL_NAV_STOP"; //$NON-NLS-1$
 public static final String IMG_ELCL_NAV_REFRESH = "IMG_ELCL_NAV_REFRESH"; //$NON-NLS-1$
 public static final String IMG_ELCL_NAV_GO = "IMG_ELCL_NAV_GO"; //$NON-NLS-1$
 public static final String IMG_ELCL_NAV_HOME = "IMG_ELCL_NAV_HOME"; //$NON-NLS-1$
 public static final String IMG_ELCL_NAV_PRINT = "IMG_ELCL_NAV_PRINT"; //$NON-NLS-1$

     public static final String IMG_DLCL_NAV_BACKWARD = "IMG_DLCL_NAV_BACKWARD"; //$NON-NLS-1$
 public static final String IMG_DLCL_NAV_FORWARD = "IMG_DLCL_NAV_FORWARD"; //$NON-NLS-1$
 public static final String IMG_DLCL_NAV_STOP = "IMG_DLCL_NAV_STOP"; //$NON-NLS-1$
 public static final String IMG_DLCL_NAV_REFRESH = "IMG_DLCL_NAV_REFRESH"; //$NON-NLS-1$
 public static final String IMG_DLCL_NAV_GO = "IMG_DLCL_NAV_GO"; //$NON-NLS-1$
 public static final String IMG_DLCL_NAV_HOME = "IMG_DLCL_NAV_HOME"; //$NON-NLS-1$
 public static final String IMG_DLCL_NAV_PRINT = "IMG_DLCL_NAV_PRINT"; //$NON-NLS-1$

     // general object images
 public static final String IMG_INTERNAL_BROWSER = "internalBrowser"; //$NON-NLS-1$
 public static final String IMG_EXTERNAL_BROWSER = "externalBrowser"; //$NON-NLS-1$
 public static final String IMG_SYSTEM_BROWSER = "systemBrowser"; //$NON-NLS-1$

     /**
      * Cannot construct an ImageResource. Use static methods only.
      */
     private ImageResource() {
         // do nothing
 }

     /**
      * Returns the busy images for the Web browser.
      *
      * @return org.eclipse.swt.graphics.Image[]
      */
     public static Image[] getBusyImages() {
         return busyImages;
     }

     /**
      * Return the image with the given key.
      *
      * @param key java.lang.String
      * @return org.eclipse.swt.graphics.Image
      */
     public static Image getImage(String key) {
         if (imageRegistry == null)
             initializeImageRegistry();
         return imageRegistry.get(key);
     }

     /**
      * Return the image descriptor with the given key.
      *
      * @param key java.lang.String
      * @return org.eclipse.jface.resource.ImageDescriptor
      */
     public static ImageDescriptor getImageDescriptor(String key) {
         if (imageRegistry == null)
             initializeImageRegistry();
         return (ImageDescriptor) imageDescriptors.get(key);
     }

     /**
      * Initialize the image resources.
      */
     protected static void initializeImageRegistry() {
         imageRegistry = new ImageRegistry();
         imageDescriptors = new HashMap ();
     
         // load Web browser images
 registerImage(IMG_ELCL_NAV_BACKWARD, URL_ELCL + "nav_backward.gif"); //$NON-NLS-1$
 registerImage(IMG_ELCL_NAV_FORWARD, URL_ELCL + "nav_forward.gif"); //$NON-NLS-1$
 registerImage(IMG_ELCL_NAV_STOP, URL_ELCL + "nav_stop.gif"); //$NON-NLS-1$
 registerImage(IMG_ELCL_NAV_REFRESH, URL_ELCL + "nav_refresh.gif"); //$NON-NLS-1$
 registerImage(IMG_ELCL_NAV_GO, URL_ELCL + "nav_go.gif"); //$NON-NLS-1$
 registerImage(IMG_ELCL_NAV_HOME, URL_ELCL + "nav_home.gif"); //$NON-NLS-1$
 registerImage(IMG_ELCL_NAV_PRINT, URL_ELCL + "nav_print.gif"); //$NON-NLS-1$

         registerImage(IMG_CLCL_NAV_BACKWARD, URL_CLCL + "nav_backward.gif"); //$NON-NLS-1$
 registerImage(IMG_CLCL_NAV_FORWARD, URL_CLCL + "nav_forward.gif"); //$NON-NLS-1$
 registerImage(IMG_CLCL_NAV_STOP, URL_CLCL + "nav_stop.gif"); //$NON-NLS-1$
 registerImage(IMG_CLCL_NAV_REFRESH, URL_CLCL + "nav_refresh.gif"); //$NON-NLS-1$
 registerImage(IMG_CLCL_NAV_GO, URL_CLCL + "nav_go.gif"); //$NON-NLS-1$
 registerImage(IMG_CLCL_NAV_HOME, URL_CLCL + "nav_home.gif"); //$NON-NLS-1$
 registerImage(IMG_CLCL_NAV_PRINT, URL_CLCL + "nav_print.gif"); //$NON-NLS-1$

         registerImage(IMG_DLCL_NAV_BACKWARD, URL_DLCL + "nav_backward.gif"); //$NON-NLS-1$
 registerImage(IMG_DLCL_NAV_FORWARD, URL_DLCL + "nav_forward.gif"); //$NON-NLS-1$
 registerImage(IMG_DLCL_NAV_STOP, URL_DLCL + "nav_stop.gif"); //$NON-NLS-1$
 registerImage(IMG_DLCL_NAV_REFRESH, URL_DLCL + "nav_refresh.gif"); //$NON-NLS-1$
 registerImage(IMG_DLCL_NAV_GO, URL_DLCL + "nav_go.gif"); //$NON-NLS-1$
 registerImage(IMG_DLCL_NAV_HOME, URL_DLCL + "nav_home.gif"); //$NON-NLS-1$
 registerImage(IMG_DLCL_NAV_PRINT, URL_DLCL + "nav_print.gif"); //$NON-NLS-1$

         registerImage(IMG_INTERNAL_BROWSER, URL_OBJ + "internal_browser.gif"); //$NON-NLS-1$
 registerImage(IMG_EXTERNAL_BROWSER, URL_OBJ + "external_browser.gif"); //$NON-NLS-1$

         // busy images
 busyImages = new Image[13];
         for (int i = 0; i < 13; i++) {
             registerImage("busy" + i, URL_OBJ + "busy/" + (i+1) + ".gif"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 busyImages[i] = getImage("busy" + i); //$NON-NLS-1$
 }
     }

     /**
      * Register an image with the registry.
      *
      * @param key java.lang.String
      * @param partialURL java.lang.String
      */
     private static void registerImage(String key, String partialURL) {
         try {
             URL url = FileLocator.find(WebBrowserUIPlugin.getInstance().getBundle(), new Path(partialURL), null);
             ImageDescriptor id = ImageDescriptor.createFromURL(url);
             imageRegistry.put(key, id);
             imageDescriptors.put(key, id);
         } catch (Exception e) {
             Trace.trace(Trace.WARNING, "Error registering image " + key + " from " + partialURL, e); //$NON-NLS-1$ //$NON-NLS-2$
 }
     }
 }

